Pearls instead of Fish King coins
At any level where you can obtain pearls, press "Select" to show the controller guide, then hold L1 and enter: OXOOOXOO

Dancing mode
To win in dancing mode, press the buttons when they get to the circle.

Destroyable creatures
You can destroy crabs, puffer-fish, guard fish, piranhas, electric eels, and angler fish. You cannot destroy jellyfish, sea urchins, bus fish, and long eels.

Chapter 3: Pearls
If you attack a puffer fish, many pearls will come out.

Chapter 9: Avoid being caught
To avoid being caught by police fish, go into houses until the cops pass. When you are going through the dining room, you can only be seen by the waiters, and not the sharks. Note: Beware of piranhas.

Chapter 9: Staying hidden
When you must sneak around the fish with lights on their heads or the ones with torches, there are some tables with cloths on them that you can go under without being detected.

Shorties
If you cannot beat the Shorties, try following them.